Photovoltaic (PV) solar arrays are typically comprised of optimizers and microinverters, commonly called Module Level Power Electronics (MLPEs) and PV Modules which are secured with structures called racking. Racking systems may include rails which support the modules or attach directly to module frames without rails. Most rooftop racking systems are designed to mount arrays with a low profile and minimal clearance from the surface to which they are attached.
Most PV components interface with standardized components, such that different brands of modules, MLPEs, racking, and wire management devices can be combined into a complete PV system. Typically, cables are terminated with industry standard connectors and are factory-connected inside the modules and MLPEs. The cables are connected and run under the modules, both parallel and perpendicular to mounting rails. In some scenarios, cables with custom lengths and matching connectors are made on-site. Both factory connected cables and cables created on site are secured so that they do not hang loose, sag, or come into contact with damaging or abrasive surfaces. The act of securing these cables is commonly referred to as “wire management.”
One common industry practice is to use zip ties or wire clips to secure wires to module frames or rails. This practice is time-consuming, lacks longevity and can easily damage the conductors. Plastic zip ties, even UV resistant versions, degrade and break with the intense UV and heat exposure common in PV solar arrays. Metal zip ties are an alternative but have sharp edges that can cut into and damage cables. Furthermore, this practice is time-consuming and requires installers to pick up, properly orient and attach small components.
All of these means of wire attachment/securing require technicians to install conductors under tension to ensure the portions spanning between attachments stay above the roof surface and do not sag. To maintain this tension, installers often pull the wires around racking components, which can abrade and cut into the wire. However, the wires are subject to thermal expansion which can significantly change the length of the wires. For example, if the wires are installed under tension on a warm day, they can shrink and pull out of the wire clip attachments in cold weather. In extreme situations, conductors can even pull out of the electrical connectors resulting in arcing, and electrical hazards.
There are various other PV wire management devices such as “Hanging Wire Ways”, “Racking Integrated” or “Rail Integrated” wire management devices. Each of these devices are difficult to install, are cost prohibitive, or require custom modules or racking. Some rails and modules have integrated wire management features, but they are not compatible to manage wires sets running perpendicular to the mounting rail. Furthermore, they lack industry standard interfacing features, which locks consumers into a specific brand.
Cable Ways are a common product used in the electrical industry. These trays are large-scale and designed for used in large commercial and industrial applications. They typically mount to structures, struts, or hangers. MP Husky, Legrand, Cooper Industries are all companies that produce cable trays. However, these trays cannot attach directly to rails and module frames, cannot clamp and secure a cable exiting the device, and do not fit in the space under standard rooftop racking systems. Therefore, they are not ideal for managing cables running under modules to connect components within the array. There are Cable Ways designed specifically for use on PV solar arrays, but they interfere with racking/mounting components when used within the array.
What is needed is a wire management system in which cables can be laid and secured without tension or contact with sharp edges, a universal system compatible with all PV modules, and a system which mounts to the module frame or mounting rails without interfering with common racking/mounting systems and MLPEs. What is further desired is a wire management system which is durable protects the wires placed within the system.